Baking-oven.



C. W. HE'LM.

BAKING OVEN.

H APPLICATION FILED SEPT.24, I9I4. P 1 1165 49,, Patented Dec. 28, 1910.

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C. W. HELM.

BAKING OVEN.

APPLICATION FILED SEPT.24. 1914.

Patented Dec. 28, 1915.

6 SHEETS-SHEET 2.

C. W. HELM.

BAKING OVEN.

APPLICATION FILED SEPT.24, 1914.

Patented Dec. 28, 1915.

6 SHETSSHEET 3.

c. w. HELM.

BAKING OVEN.

APPLICATION FILED SEPT.24, m4.

1,165.,QQ9'. Patented Dec. 28, 1915.

6 SHEETS-SHEET 5.

C. W. HELM.

BAKING OVEN.

APPLICATION FILED SEPT-24, 1914.

Patented Dec. 28, 1915.

6 SHEETSSHEET 6- C. WELLS HELM, OF CHICAGO, ILLINOIS.

BAKING-OVEN.

Specification of Letters Patent.

Patented Dec. 28,1915.

Application filed September 24, 1914. Serial No. 863,263.

To all whom it may concern:

Be it known that I, C. WELLS HELM, a

- resident of Chicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Baking- Ovens, of whichthe following is a full, clear, and exact description.

The invention relates to baking ovens.

In baking ovens, a desideratum is to provide a baking chamber of maximumarea to give the greatest baking capacity. In these ovens, it iscustomary to provide flues for the products of combustion in the cornersof the walls of the oven and heretofore the capacity of the bakingchamber was materially lessened by the necessity of provldmg asufficient thickness of wall between the One object of'the invention isto provide an improved baking oven in which the fiues for the productsof combustion are disposed in the corners of the structure forming thewalls of the oven and in which an increased baking capacity is attainedby providing a structure which permits a comparatively thin dividingwall between the flues and the baking chamber, provision being made toprevent burning of the bread in the baking chamber and adjacent thefines by heat insulation. As a result of this construction, the capacityof-the baking chamber is increased and a wider front opening is possibleso that a pair of charging openings or doors may be installed for thebaking chamber, and. charging of the baking chamber and removal of thebread therefrom may be more readily and quickly done because the slopingside-walls adjacent the front of the oven may be formed at a less acuteangle than has heretofore been possible.

A further object of the invention is to provide an improved fire box forthe oven which has a maximum capacity permitted by the walls of the ovenand which is so formed that likelihood of coke being thrown to the rearof the fire box, as frequently occurs in ovens now in use, will beavoided.

A further object of the invention is to provide an 1mproved front forthe baking chamber which is adapted for and provided with a pair ofcharging doors WhlCh'PBIIllll] ready access to all portions of thebaking chamber. 1

A further object of the invention is to provlde means for regulating thetemperature of the baking oven by varying the air current passingthrough the air space between the top of the combustion chamber and thebottom of the baking chamber, so that the cooling effect of the air maybe regulated as may be desired in baking.

A further object of the invention is to provide improved means forinsulating the bottom of the oven from the floor of the buildin where itis erected on a floor and'this ob]ect is attained by the use ofalternating layers of cork brick and hollow tile and asbestos fire boardwhich do not materially providing a curved area of fire brick which doesnot crack as a straight wall of tile does.

Lastly, the invention designs to provide a baking oven of improvedconstruction.

The invention consists in the several novel features hereinafter setforth and more particularly defined by claims at the conclusion thereof.

In the drawings: Figure 1 is a vertical longitudinal section of an ovenembodying the invention. Fig. 2 is a transverse section taken online 22of Fig. 1. Fig. 3 is a horizontal section taken on line 33 of Fig. 1.Fig. 4 is a horizontal section taken on line 4-4: of Fig. 1. Fig. 5 is adetail plan of one of the charging doors, parts being shown in section.Fig. 6 is a front view of the parts shown in Fig. 5. Fig. 7 is a detailand the lighting apparatus at one end thereof. Fig. 9 is a detail of thedraft-regulating apparatus for the air chamber below the baking chamber.

The improved baking oven comprises a structure of masonry 15, formingthe walls of the oven in which are formed a fire box 16. a combustionchamber 17, a baking chamber 20, an air chamber 18, disposed between theroof 19 of the combustion chamber and the fioor 21 of the baking chamberand smoke fines Usually a tile-brick facing 22 is provided at the frontof the oven. A suitable door 24 is disposed at the rear of the oven andthrough this door, fuel, usually coke, may be fed to the fire-box 16. Inmany instances, it is desirable to install these ovens upon a floor thatis without special support or not specially constructed for these ovensand in such instances, it is desirable to insulate the oven from thefloor and to prevent the heat from passing through the floor and toavoid the weight of a thick base under the inclosing structure of theoven for the purpose of insulating the oven from the floor of thebuilding. To meet these conditions, the base of the oven structureconsists of a course of insulating material 25, such as asbestos uponwhich are laid alternate courses of hollow tile 26 and corkbrick 27. Twocourses of hollow two inch tileand two courses of four inch cork brickhave been found, in practice, to eiiiciently insulate the lower portionof the oven from the floor without unduly increasing the weight of theoven structure. This cork brick, which is composed of mixeddiaton'iaceous earth and ground cork, provides eflicient lnsulatlon andis much lighter than refractory material, and the alternate courses ofhollow tile provide for efficient insulation and support the ovenstructure above the base.

A desideratum in baking ovens is to provide a fire box of maximum depthand capacity and one which will prevent the fuel or coke from beingthrown backwardly upon the floor 28 of the combustion chamber where itwill not be consumed and, therefore, wasted. This requirement isattained by providing a. fire box of increased depth and stepped orterraced brickwork above and around the back and sides of the gratebars, as at 29. Grate bars 30, in desired number are supported uponrails 31. By placing these grate bars lower than has heretofore beendeemed possible, the top of the fuel door 24 will be disposed so lowwith respect to the floor 28 of the combustion chamber that the cokewill pile up in the box and not be thrown onto said floor. As a resultof this construction, no ashes or coke will be carried or thrown ontothe floor of the combustion chamber where they will interfere withcombustion and clog the combustion chamber. This construction is suchthat a careless fireman, in charging the fire box, will not throw thecoke in back of the fire box, and the fuel capacity is increased by thestepped sides and back of the fire box.

The roof 19 of the combustion chamber is arched transversely and extendsrearwardly to a cross flue EH which conducts the products of combustionto two stacks or upright fines which are disposed adjacent the frontcorners of the structure and lead into horizontal spaces 35)- above theroof of the baking chamber and may be connected, in manner wellunderstood in the art, to the chimney. The top of the cross fine at theback of the combustion chamber has hereto fore been formed of straightor horizontally laid tile. In practice, it has been found that suchformation becomes cracked, permitting the products of combustionto workthrough to the air chamber 18 and t burn the goods in the bakingchamber. 0 overcome this objection. an arch 3(3 of fire brick is formedat the back and top of the cross flue and rear of the combustionchamber. In practice, it has been found that this arch effectivelyprevents cracking of the wall at the rear end of the combustion chamberand the cross lines and thus the leakageof the products of combustioninto the air chamber where they will contact with the floor of thebaking chamber is eliminated.

I-Ieretofore, it has been the practice to build a thick wall ofrefractory material between the upright fines 35 and the baking chamberto prevent the bread in the front portion of the baking chamber frombeing burned. It has been necessary to form that wall so thick that thecapacity of the baking chamber was materially lessened and furthermore,the opening for the door at the front of the oven was restricted so thatthe side portions of the baking chamber were not readily accessible andcould not be Well illuminated for inspection. To overcome thisobjection, a filling or course of asbestos 38 is built into the wallbetween the upright fines 35 and the side of the baking chamber, thisasbestos being disposed and extending adjacent and around the inner sideand rear of the fines. By employing asbestos in this manner, it hasbecome possible to very materially reduce the thickness of the, wallbetween the fines 35 and the baking chamber without danger of burningthe bread in the baking chamber from the heat in the upright fines. Inreducing the thickness of this wall, the capacity of the baking chamberis increased and the opening at the front of the baking chamber for thedoor or doors may be extended much closer to the upright fines than hasheretofore been possible. Furthermore, by reducing the acuteness of thesides of the baking chamber adjacent its front,

the chamber may be more conveniently charged and unloaded.

An air space 40 is formed in the structure and extends around the back,sides and front thereof. Screened-inlets 4:1 permit air to pass from theoutside to space l0 and also serve as openings which give access to thecross flue 31 and the back of the combustlon chamber 17. Ducts 41, oneat each side of the oven, connect air space 40 with the air chamber 18which is disposed between the roof of the combustion chamber and thefloor of the baking chamber. At the rear of the structure, air chamber40 is connected by ducts 45' {one at each side, with a flue 46 whichcommunicates with the smoke passages 35. At the front and back of airchamber 18, channel irons 18 are secured in the structure and thesechannel irons are provided with openings 49 for the inlet and egress ofair respectively. Valves 50, are slidably mounted upon the channel bars48, respectively and are adapted to close the openings 49 more or lessto regulate the circulation of air through chamber 18. A rod 51 issecured to both valves 50 and is extended to the front of the structure,as at 52,

for convenience in manipulating the val .es.'

It will be understood that a rod 51 and a pair of valves 50 are providedfor each side of the oven. These valves exemplify means for regulatingthe flow of air through the chamber 18 to vary the cooling effect of theair upon the baking chamber.

A flue 54 leads from the top of the baking chamber to outlet 46 to carryoff condensation from the baking chamber, and a suitable valve 55secured to a rod 56, which is extended to the front of the oven, isprovided for the manipulation of said valve. Abutment rails 60,buckstays 61 and the rods 62 are used to reinforce the structure, aswell understood in the art.

As a result of the narrowing of the walls between the upright flues 35and the sides of the baking chamber, it is possible to convenientlyemploy two charging doors for the baking chamber. Each door structurecomprises a rectangular'frame 61 which fits around each door-opening 62of the structure, and a door 63, which is pivoted as at 64 in the sides65 of a frame 61. A shield 66 extends from the door pivot to the topwall 67 of each frame 61. A plate 68 eX- tends from the lower frontportion of each frame 61 tothe floor 21 of the inclined baking chamber.Counterweights 69 are suitably secured to the pivot of each door, which,when the door is shifted into open position, serve to hold the doorsopen and also serve to hold the doors closed. The housing 70, for eachcounterweight, is set into the front wall of the structure 15.

A housing 72 is secured to the top of wall 67 of the door frame, and oneof these housings is secured adjacent each end of each door 'frame,thusmaking provision for two lights above each door. These housingsextend through the wall at the front of the baking chamber and eachcontains an incandescent electric lamp 75 and a reflector 76. The lamp75 and the reflector 76 are secured to a support or tube 78which'contains the electrical connections for the lamp and plug contacts79 which are adapted to be inserted into socket-contacts 83,84 in ablock 81. By moving the rear end of tube 78-sidewise to withdrawcontacts 79, 80 from block 81. the lamp and tube may be disconnectedfrom the block so that the tube, lamp and reflector may be withdrawnthrough a remow able front door 82. This construction permits the lightsto be readily placed into the housing 72 to be removed therefromwhenever a lamp is to be replaced or the reflector is to be cleaned, andalso permits one lighting apparatus to be removed if only one is deemednecessary. One of the leading-in conductors 85 isconnected to socketcontact 84 and the other to a contact 86. A short onductor 87electrically connects contact 83 to a contact 88. A two-armed switch 89is secured to the door pivot Gland is operated by the door so that whenthe door is open, the switch will be closed to light the lamp 75 andwhen the door is closed, the switch will be opened.

As a result of disposing the light housngs 72 on the top of the doorframe. the light is diffused in the baking chamber and s disposed abovethe point of view so that shadows will be avoided, and the contents ofthe baking chamber may be readily seen through a door. As a result ofemploying the housing 72 around the tube 78 and extending through thewall at the front of the baking chamber, the leakage of steam isavoided. As a result of employing the light-support or tube 78 with itscontacts separable from its fixed contacts on block 81, the removal andreplacement of the lamp and reflector are greatly facilitated.

The invention is not to be understood as restricted to the details setforth, since these may be modified within the scope of the appendedclaims, without departing from the spirit and scope of the invention.

Having thus described the invention, what I claim as new and desire tosecure by Letters Patent, is:

1. In a baking oven, the combination of a structure, having a fire boxand a baking chamber therein, and a base for the structure comprisingalternate courses of hollow tile and cork brick.

2. In a baking oven, the combination of a structure having a fire boxand a baking chamber therein, and an insulating base for the structurecomprising a lower course of heat-insulating fiber and alternate coursesof hollow tile and cork brick.

3. In a baking oven,the combination of a structure provided with. ahorizontally extending combustion-chamber, a baking chamber above thecombustion chamber and a fire box disposed at one end of the combustionchamber and having grate bars therein, a fuel door leading to thefire-box, and a stepped wall between the grate-bars and the floor of thecombustion chamber.

4. In a baking oven, the combination of a structure provided with ahorizontally extending combustion chamber, a baking chamber above thecombustion chamber and a fire box disposed at one end of the combustionchamber and having grate bars therein and a fuel door leading to thefire box, the fire box having stepped side and end walls and extendingfrom the grate bars to the floor of the combustion chamber.

5. In a baking oven, the combination of a structure having a fire box ahorizontally extending combustion chamber and a baking chamber thereinand having an air chamber between the fire box and the baking chamber.upright flues adjacent the corners of the structure, a cross flue at thehack of the combustion chamber leading to the upright flues, and an archof fire-brick at the back and top of the cross-flue.

6. In a baking oven, the combination of a structure having a fire box a.horizontally extending combustion chamber and a baking chamber thereinand having an air chamber between the fire box and the baking chamber,upright fiues adjacent the corners of the structure, a cross flueextending laterally from both sides of the back of thecombustion-chamber leading to the upright fiues, and an archof firebrick at the back and top of the combustion chamber and the cross flue.

7. In a baking oven, the combination of a structure having a fire boxand a baking chamber above the fire box, upright flues in the corners ofthe structure communicating with the fire box, the structure having awall between each of the upright fiues and the baking chamber, and acourse of heat-insulation in said Walls for preventing overheating ofthebaking chamber by the products of combustion in said flues.

8. In a baking oven, the combination of a structure having a fire boxand a baking chamber above the fire box, upright fiues in the corners ofthe structure communicating with the fire box, the structure having awall between each of the upright flues and the baking chamber and acourse of heat insulating material in said walls and disposed inwardlyand rearwardly of the fiues for preventing overheating of the bakingcham er by the products of ombustion in said fines.

9. In a baking oven, the combination of a structure having a fire boxand a baking chamber. therein and having an air chamber between the topof the fire box and the bottom of the baking chamber, air ducts at thefront and back of said air chamber, respectively, valves at the frontand back of said chamber for regulating the flow of air through saidchamber and a connection between said valves whereby they will beconjointly shifted.

o. WELLS HELM.

\Vitnesses:

MILDRED STUMPF, KATHARINE GERLACH.

